DPARAM(ADM) UNIX System V
Name
dparam - displays/changes hard disk characteristics
Syntax
dparam [ -w ]
dparam /dev/rhd[0|1]0 [characteristics]
Description
The dparam command displays or changes the hard disk
characteristics currently in effect. These changes go into
effect immediately and are also written to the master boot
block for subsequent boots. If a non-standard hard disk is
used, this utility must be called before accessing the
drive.
-w Causes a copy of /etc/masterboot to be copied to
disk to ensure that non-standard hard disks are
supported for the specified drive. This call must
precede a call to write non-standard disk parameters
for the desired parameters to be saved correctly in
the masterboot block.
When called without options or disk characteristics, dparam
prints the current disk characteristics (on the standard
output) for the specified hard disk. These values are
printed in the same order as the argument list.
When writing characteristics for the specified hard disk,
dparam changes the current disk controller status and
updates the masterboot block. The argument ordering is
critical and must be entered as specified below. All
characteristics must be entered when writing disk
characteristics, otherwise an error is returned. Hard disk
characteristics (in respective order) are:
number of cylinders
total number of cylinders on the hard disk
number of heads
number of heads
write cylinder
hardware specific, consult your hardware manual
write precompensation cylinder
hardware specific, consult your hardware manual
ecc number of bits of error correction on I/O
transfers, consult your hardware manual
control very hardware specific, consult your hardware
manual
landing zone cylinder
where to park heads after shutting down the
system
number of sectors per track
number of sectors per track on the hard disk
Examples
dparam -w
dparam /dev/rhd10
dparam /dev/rhd00 700 4 256 180 5 0 640 17
Notes
This utility changes the kernel's view of the hard disk
parameters. It may be subject to restrictions imposed by the
hardware configuration.
Value Added
dparam is an extension of AT&T System V provided by the
Santa Cruz Operation.
(printed 2/15/90) DPARAM(ADM)